For decades, Soviet soldiers and officers and later their Russian civilian successors had to brave winter cold and summer heat preparing Soyuz rockets for launch on open-air gantries in Baikonur and Plesetsk. But in a sign how times have changed, the new generation of rocketeers will be protected from snow and rain with a climate-controlled tower completely enclosing the Soyuz rocket before liftoff from its newest launch pad at Russia's Vostochny Cosmodrome.

By 2015, the Mobile Service Tower, MBO, (back view) appeared sporting unorthodox paint job, which was promised to be color-coordinated with all other facilities of Vostochny.

The original design of the Mobile Service Tower, MBO, featuring Russian tri-color.

The nearly completed MBO in the summer of 2015 in its parking position near the launch pad.

The completed Mobile Service Tower withdraws from the first Soyuz rocket to be launched from Vostochny on April 28, 2016.

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Painted in elegant blue and white and standing almost 50 meters high, the Mobile Service Tower, MBO (for Mobilnaya Bashnya Obsluzhivaniya), is designed to provide personnel access to the Soyuz rocket during the countdown to liftoff from its launch pad in Vostochny. The structure can be also used to service the pad after launch and to process the rocket in case of an aborted liftoff.

With the tower in place, technicians can easily reach practically any part of the rocket as high as 37 meters above the surface of the launch pad. Internal access bridges of the tower surround the upper portion of the first and second stage, the third stage and the payload fairing.

Along with the rocket and the personnel, the tower also shelters several key systems of the Soyuz launch complex in Vostochny, which are open to the elements in Baikonur and Plesetsk, including the Service Cabin, a pair of fueling and umbilical gantries and four support truss structures.

Unlike the movable tower for the Soyuz complex in Kourou, French Guiana, which was built by a company specialized in amusement park structures, the MBO tower for Vostochny was developed by bridge engineers at NPO Mostovik in Moscow and manufactured at the company's ZMK Mostovik factory (Zavod Metalo-Konstruktsiy) in the City of Omsk. The metal structure of the tower was assembled out of 376 components, which themselves were made out of 3,100 elements.

The tower is equipped with elevators, cranes, ventilation and climate control equipment. A special emergency evacuation system, SAE, was built in. Soyuz rockets built for launches from Vostochny would be equipped with special valves to drain excess propellant outside of the tower to prevent dangerous concentration of oxygen vapors in its interior.

Specifically for the tower, a dual railway was laid with an accuracy of just five millimeters to ensure the precise positioning of the structure over the rocket. The rails are resting on 282 foundation pads with a mass of 450 kilograms each.

Pre-launch operations

The MBO tower is designed to move with a speed of up to 12 meters per minute on four boogies to traverse the 80 or 100 meters from its parking position outside the launch pad to the launch platform. It would normally take around 10 minutes for the MBO to complete its trek.

The back wall of the tower has a small set of doors, which enable the passage of the transporter/erector with the Soyuz rocket in horizontal position, when the tower is in its parking position. On its facade, the MBO sports its main tall doors, which allow the tower to roll onto the rocket after the vehicle has been erected into vertical position, typically two days before launch.

After the personnel completes the preparation and testing of the rocket around 24 hours before launch, the fueling of the Soyuz rocket begins several hours before launch.

Around an hour before the completion of the fueling, the tower is rolled back to its parking position to clear the launch pad for the final countdown and liftoff.

The first components of the movable tower were assembled at ZMK Mostovik in Omsk in September 2013. The assembly of the tower in Vostochny started in 2014 and its main structure was completed and powered up in July 2015. Roofing and wall paneling was conducted in August 2015.

Known specifications of the Mobile Service Tower:

Total height

*48.3 meters

Width

24.1 meters

Depth

24.8 meters

Speed of movement

12 meters per minute

A total mass

1,600 tons

Mass of metal structure

580 tons

*52 meters according to other sources

Alternative variants

Three variants of the Mobile Service Tower were proposed during the preliminary design of the system.

Variant 1 featured a tower moving on two rail tracks with a track width of 1,520 millimeters and a width between axis 23.3 meters. The structure had doors on both sides and rotating access bridges all equipped with their own driving mechanisms. The winning design was apparently based on that variant.

Variant 2 included a tower moving on two rail tracks with a track width of 1,000 millimeters and a distance between axis of 23.3 meters. It also had doors on both sides, which had one common driving mechanism for all doors and access bridges.

Variant 3 proposed a two-section tower whose halves would be moving on two rail lines extending perpendicular to the main railway for the delivery of the rocket. Tracks also had a width of 1,520 millimeters and a distance between axis of 23.3 meters.

Known specifications of three proposed variants of the Mobile Service Tower:

Specification

Variant 1

Variant 2

Variant 3

Total height

49.6 meters

54.0 meters

45.8 meters

Total width

26.1 meters

29.0 meters

Two sections each 24.2 meters

Total depth

31.3 meters

28.0 meters

27.8 meters

Mass of metal structure

670 tons

?

700, plus 400 for counterweights

High-strength bolts

(19,000 pieces) 13.7 tons

?

(20,800 pieces) 15.0 tons

Access bridges

135 tons

?

130 tons

Stairs

30 tons

?

50 tons

Elevator shaft

12 tons

?

24 tons

Roof structure and water drainage

32 tons

?

6 tons

Sidings

82 tons

?

100 tons

Emergency evacuation system bridges

40 tons

?

40 tons

Moving mechanism

90 tons

?

100 tons

Total mass

1,105 tons

?

1,544 tons

Maximum speed

up to 5 kilometers per hour

?

?

Number of door moving mechanisms

6

10

none

Number bridge access mechanisms

20

8

none

Number of buggies

4 (4-axis)

?

12 (2-axis)

Number of internal staircases

1

?

?

Number of external staircases

1

1

2

Number of elevators

1

2

2

Read much more about the history of the Russian space program in a richly illustrated, large-format glossy edition:

The article and photography by Anatoly Zak; Last update:
November 23, 2017

Page editor: Alain Chabot; Last edit: August 8, 2015

All rights reserved

IMAGE ARCHIVE

The exterior design of the Mobile Service Tower as of summer 2015. Credit: Roskosmos

The movable base of the service tower appeared in Vostochny in the fall of 2014. Credit: Roskosmos

Click to enlarge. Credit: Spetsstroi

The Mobile Service Tower, MBO, takes shape at the Soyuz pad in Vostochny at the end of 2014. Click to enlarge. Credit: Spetsstroi

The Mobile Service Tower, MBO, in February 2015. Credit: Russian TV

The main structure of the movable service tower was completed by the end of March 2015. Click to enlarge. Credit: Spetsstroi

The Mobile Service Tower is getting its wall panels in August 2015. Click to enlarge. Credit: Roskosmos

Soyuz rocket support structure inside the Mobile Service Tower during its testing in August 2015. Click to enlarge. Credit: Roskosmos